I'm trying to prep the hood of my truck, actually removing red stains from tree. I used 6 inch fine nanoskin pad with my GG6 and nanoskin glide. All stains were removed and visibly all looks good. Baggie test reveals bumps or roughness. Is this something that a medium pad or straight clay would take care of, or do I need Iron X. This is 2006 Silverado work truck that is outsie 24/7